An enormous black hole one hundred thousand times more massive than the sun has been found hiding in a toxic gas cloud wafting around near the heart of the Milky Way.

If the discovery is confirmed, the invisible behemoth will rank as the second largest black hole ever seen in the Milky Way after the supermassive black hole known as Sagittarius A* that is anchored at the very centre of the galaxy.

The smallest black holes form when particular types of stars explode at the end of their lives. According to scientists’ calculations, the Milky Way is home to about 100m of these smaller black holes, though only about 60 have been spotted.

But astronomers also know that much larger, supermassive black holes lie at the heart of large galaxies including the Milky Way, where Sagittarius A* weighs as much as 400m suns. What is unknown is how these supermassive black holes form.

One theory is that smaller black holes steadily coalesce into larger ones and these come together to form supermassive black holes at the hearts of galaxies, but until now, no definitive evidence for intermediate mass black holes has been found. The detection of a potential black hole weighing as much as 100,000 suns is precisely the middle step in the process that astronomers have sought.

You could think of the universe as a 3 dimensional bowl of water with bits floating in it, that due to surface tension will all end up together in the same place at one point. Or as a pan of bubbling soup with big bangs everywhere.

Rainer Weiss, Kip S Thorne and Barry C Barish share the Nobel Prize for its groundbreaking research on gravitational waves. The three Americans made the discoveries possible through the Gravity Observatory Ligo, which has found waves after four major events.

LIGO includes two interferometers, one in Louisiana and the other in Hanford,Washington State.The fourth event was also observed by VIRGO, a French Italian joint venture in Cascina,Pisa. Ron Drever from UK would also have deserved the prize, but he died this year.
Tullio

Signal GW170817 was not emitted by black holes at billion light years distances but by a merger of two neutron stars al 130 million light years seen by LIGO and Virgo. The event produced radio, optical and gamma-ray emissions seen by almost 100 telescopes both on Earth and in space. This is the first time that a merger of two neutron stars is observed.
Tullio

Signal GW170817 was not emitted by black holes at billion light years distances but by a merger of two neutron stars at 130 million light years seen by LIGO and Virgo. The event produced radio, optical and gamma-ray emissions seen by almost 100 telescopes both on Earth and in space. This is the first time that a merger of two neutron stars is observed.
Tullio

The gamma-ray burst was detected 1.6 s after the GW, which hit first the Virgo detector and second the LIGO interferometers. What was lacking was x-rays, seen only after a week. A number of phenomena wait for an explanation. GW astronomy has started, and I want to remember Joseph Weber, who pioneered the field and had little recognition. In 1970 I published an article on General Relativity by Peter G.Bergmann, and put a photo of one of Weber's detectors in its front page.
Tullio

There are two open articles on "Nature Research" with many details. All astronomy is in turmoil, this is the first time that a source of GW has emitted also in the EM spectrum. Thanks to Edoardo Amaldi,who inspired the Istituto Nazionale di Fisica Nucleare to build Virgo, with the help of French CNRS.
Tullio

Tulio, I was thinking and wondering about the energy converted into GW waves and its propagation.

When we think of EM waves we know they transfer their energy to other matter when they run into it. That means we have shadows where the EM radiation is blocked by matter. Does that apply to GW radiation?

That brings up the question of when a GW wave passes through a body such as the earth, does it transfer energy to it? If so does that increase the temperature? (not that we could ever measure it)

I was starting to think about an otherwise empty universe with two block holes in orbit. With the rest being empty their radiated energy continues out forever. Does that violate entropy in some way?

How does this all interact with virtual particle pairs? Does this potential energy change the fundamental constants to make such production more likely?

Gravitational radiation is a quadrupole radiation and is very weak. I have searched all available literature for its energy density and I found only a case, cited by Remo Ruffini then at Princeton University, in a 1973 article I had translated and published. The gravitational radiation produced by the binary Sirius system, with M1 =0.98 solar masses and M2 =2.28 solar masses is 10 to the seventh power joule/s with a revolution period of 50 years. Very weak. Now binary black holes and binary neutron stars can produce much more but they are also very far.
Tullio
From the January 2017 issue of CERN Courier I learn that the power emission of two black hole mergers which produced GW was of 10 to the 49 power joule/s. But they were billions of light years away.

Precise comparisons of the fundamental properties of matter–antimatter conjugates provide sensitive tests of charge–parity–time (CPT) invariance1, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons2, leptons3, 4 and baryons5, 6 have compared different properties of matter–antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level7, 8: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron3. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result = −2.7928473441(42)μN (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement8 by a factor of approximately 350. The measured value is consistent with the proton magnetic moment9, μp = 2.792847350(9)μN, and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects10 to below 1.8 × 10−24 gigaelectronvolts, and a possible splitting of the proton–antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10−12 Bohr magnetons11.